Fluorine nmr spectroscopy will be used to examine several calcium-binding proteins isolated from the muscles of rabbits that have been maintained on a diet containing p-fluorophenylalanine. Initial experiments with other proteins have shown that incorporation of this fluoroamino acid into proteins takes place at high enough levels that fluorine nmr experiments are feasible and, given the composition and molecular weight of the proteins to be studied, it is expected that a resolved resonance for each phenylalanine residue will be observed. Systems to be examined include parv-albumin, troponin C, calmodulin and myosin light chains. Strategies for assignment of the observed signals to particular positions in the amino acid sequences will be developed. The nature of the local environment around each fluorine nucleus will be examined by fluorine-proton nuclear Overhauser effects and compared, where possible, to x-ray results. Large conformational changes are known to take place when metal ions bind to these proteins and these changes will be explored by chemical shift and relaxation rate studies as well as Overhauser effects to determine the similarities and differences in the structural transitions evoked by different metals. Conformational changes attending protein-protein interactions in these materials will be examined, as will the effects of drug-binding on conformation and metal binding ability.